There are various medical procedures, such as, for example aquadissection, injecting medication or contrast substances, cleansing or lavage of a deep area , disinfecting, and so forth, which must be performed using high pressure.
The pressurized liquid expelled through the end of the hand piece initially needs to be under sufficient pressure from the compression gas, but also requires a high pressure type conduit connecting it with the hand piece and a calibrated outlet opening with a shape and diameter corresponding to the type of spray used for the designated application.
Publication WO 94/28807 of SAPHIR MEDICAL concerns a surgical aquadissection apparatus formed of a physiological serum generator contained in a pouch under pressure in a chamber sealed with pressurized gas and connected to a hand piece by a flexible conduit, which in turn is connected to a circuit leading from the pouch through a sterile pin, penetrating one of the chamber walls through a cone-shaped seal.
A circuit terminating in a hand piece is connected to a suction pump for suctioning the liquid and evacuating fragments tissue produced during the aquadissection procedure.
This invention has a single objective: providing a generator for use in surgical dissection which emits a spray of sterile liquid.
To achieve this objective, the physiological serum must be projected at high pressure that can be regulated manually by the operator.
This is accomplished by maintaining a constant pressure, or incision pressure, at the outlet of the hand piece. An electronic regulating circuit maintains constant pressure in the sealed chamber. As a result, the incision pressure is consistently maintained at the optimal level for the surgery being performed.
Other inventions concerning generators of this type are Publication No.
EP 0 411 170, and U.S. Pat. No. 4,913,698 ITO. These concern the production of a concentrated, high pressure spray for performing aquadissection.
However, there are other instances, such as medical, surgical, and related applications, where the use of high pressure is not advisable. This is the case for pulverization, rinsing, spraying, humidifying, contact disinfection, impregnation, or irrigation with a stream of liquid.
These other applications require a different type of generator, as the procedures require that the liquid not be produced using pressure. On the contrary, a low pressure stream of liquid is desired.
One illustration of a flow generator can be found in Publication No. WO 94/27659 filed by GUIGNARD.
This physiological liquid generator also consists of a pouch holding the liquid, with the pouch subjected to propelling pressure in a sealed chamber. The pressure source is a bottle of neutral gas under pressure. The gas pressure is stringently regulated by a pressure sensor and regulator. A safety valve is adjusted to 30 kPa, or 0.3 bars. This low pressure is appropriate for an endoscopy procedure. It is actually possible to inject only low pressure liquids into the human body.
However, this generator delivers a large volume of liquid, as it also supplies a clarifying liquid for improving visibility in the surgical field. Of course, this liquid is evacuated to eliminate abnormal organ swelling and diffusion of the liquid throughout the body, and a peristaltic extraction pump is provided for this purpose.
This generator has limited pressure and cannot be used in procedures where pressure is required for the procedure, for example, dissection.
It is apparent that the different requirements described above cannot be satisfied by a single generator-dispenser using the same element to connect it with a hand piece which is interchangeable depending upon the function or application.
The goal of the present invention is to provide a single liquid generator-dispenser used in two alternating functions or modes, which eliminates slow, labor-intensive manipulations, and affords a high degree of precision under sterile conditions compatible with medical and surgical requirements.
More specifically, the goal of the present invention is to achieve a bifunctional, multi-purpose, sterile generator-dispenser which functions both as a pressure generator and a delivery generator with only one simple modification.
Yet another goal of the invention is to furnish a sterile, bifunctional generator which can function as either a pressure generator or a delivery generator depending upon either the connecting element selected, preferably a disposable element, or the control exerted on a hydraulic component, thus ensuring that it remains sterile, providing a bifunctional device at far less cost than a device with two juxtaposed functions.